Background image css not display in IE7, IE8

Question

I am trying to give a background image to div using css. This is my css

.header {
    background: url("../images/header1.png") no-repeat scroll right 15px rgba(0, 0, 0, 0);
    height: 55px;
    padding: 5px 0 0;
    width: 100%;
}

This works fine on firefox & chrome even on IE9 & IE10 also but its not working in IE8 or older versions. I have googled & also refered this question but its not helping.

Background image not showing IE8

Answer 1

rgba not supported in IE7/ IE8 http://css-tricks.com/rgba-browser-support/

Answer 2

 .header
    {
    background: url("../images/header1.png");
    background-repeat:no-repeat;
    background-position:right 15px;
    height: 55px;
    padding: 5px 0 0;
    width: 100%;
    }